A bright-eyed Barnard College freshman was showing signs of improvement yesterday as cops hunted for the hulking thug who savagely mugged her in Riverside Park, leaving her bloodied and unconscious on a bench, according to the New York Post.

Marisa Cortright, 19, of Salem, Ore., suffered bleeding on the brain, a fractured cheekbone and facial cuts in the attack at 6 a.m. Monday near the West 120th Street tennis courts. She was in stable condition at St. Luke's Hospital.

"People do not deserve to be treated this way, especially those who have made so many people appreciate, laugh and think more than they had before," Marin Fanjoy-Labrenz, 19, Cortright's roommate at Barnard, told The Post.

"She was simply going about her daily workout routine . . . She's a sweet, hilarious girl and a friend to all."

While she jogged, Cortright was grabbed from behind, punched in the face and had her head slammed into a wall by the thug, police sources said. Her iPod was stolen.

Cortright was found by tennis players.

"She doesn't remember anything," a police source told The Post.

Cops released a sketch of a 6-foot-2, heavyset black man in his mid-40s seen leaving the park following the attack.

The man -- described as a person of interest to investigators -- was wearing a bright blue, long-sleeved T-shirt and black pants.

Yesterday afternoon, Cortright appeared groggy as she sat up in her hospital bed under the watchful eye of a nurse.